“It is an infantile superstition of the human spirit that virginity would be thought a virtue and not the barrier that separates ignorance from knowledge.”

It is clear that the individual who persecutes a man, his brother, because he is not of the same opinion, is a monster.

Prejudices are what fools use for reason.

Men will always be mad, and those who think they can cure them are the maddest of all.

May God defend me from my friends: I can defend myself from my enemies.

Think for yourself and let others enjoy the privilege of doing so too.

Sensual pleasure passes and vanishes, but the friendship between us, the mutual confidence, the delight of the heart, the enchantment of the soul, these things do not perish and can never be destroyed.

To the living we owe respect, but to the dead we owe only the truth.

Our labour preserves us from three great evils – weariness, vice, and want.

It is with books as with men: a very small number play a great part.

Doctors put drugs of which they know little into bodies of which they know less for diseases of which they know nothing at all.

The only way to comprehend what mathematicians mean by Infinity is to contemplate the extent of human stupidity.

Love is a canvas furnished by Nature and embroidered by imagination.

There are truths which are not for all men, nor for all times.

When it is a question of money, everybody is of the same religion.

Opinions have caused more ills than the plague or earthquakes on this little globe of ours.

I have chosen to be happy because it is good for my health.

Technology is unlocking the innate compassion we have for our fellow human beings.

Give yourself a break. Stop beating yourself up! Everyone makes mistakes, has setbacks and failures. You don’t come with a book on how to get it right all the time. You will fail sometimes, not because you planned to, but simply because you’re human.

Nobody is more dangerous than he who imagines himself pure in heart; for his purity, by definition, is unassailable.

I could go days, weeks, without talking to another human being.

Before I speak, I have something important to say.

It’s amazing how much panic one honest man can spread among a multitude of hypocrites.

Experience is merely the name men gave to their mistakes.

The future of humanity is going to bifurcate in two directions: Either it’s going to become multiplanetary, or it’s going to remain confined to one planet and eventually there’s going to be an extinction event.